In a conventional glass plate cutting device, that is, in a breaking line forming device, a threaded shaft is connected to a moving base to which a cutter head is mounted and also connected through a pulley, a belt, etc., to a rotational output shaft of an electric motor, which is rotated and hence the threaded shaft is rotated to move the moving base, for example, in the direction of X. A threaded shaft is connected through a nut to a bed on which a glass plate is placed. The threaded shaft is connected through a pulley, a belt, etc., to the rotational output shaft of an electric motor, which is rotated and hence the threaded shaft is rotated to move the base, for example, in the direction of Y. Thus, a cutter wheel of the cutter head is moved along a cutting or breaking line to be formed on the glass plate.
In this conventional apparatus, the relatively long threaded shaft is rotated, so that large bending vibrations occur on the threaded shaft in a dangerous speed region. Thus, it is difficult to rotate the threaded shaft at high speed to move the moving base and bed at high speed to thereby improve the working efficiency.
The present invention is made in view of the above problems. It is an object of the present invention to provide a glass plate cutting device which is capable of moving the cutter head at high speed and accurately along a cutting line to be applied on a plate of glass, improving the working efficiency and providing a high quality product.